# Parallax videos

This is the README file for the parallax videos produced in the [Astronomisches Rechen-Institut](http://www.ari.uni-heidelberg.de)
([ZAH](http://www.zah.uni-heidelberg.de), [Universität Heidelberg](http://www.uni-heidelberg.de)).
The parallax videos are a series of videos that intend to demonstrate the concept of parallax in the field of astronomy in general
and Gaia in particular.

## Description of the files

There are two folders, `avi` and `mp4`. You should get the videos from the `avi` folder, the `mp4` contains the same videos in other formats.

These videos intend to demonstrate the parallax effect by using a camera on the Earth, whose orbit around the
Sun is scaled by a factor of `1E5` (one hundred thousand). If you require the scripts used to generate the Partiview
`flypath` files contact the author. 
Here is a description of the contents of the videos in `avi`. By default the proper motion of the stars is **not**
activated unless specified otherwise in the description.


|**File name**                                   | **File size**         | **Description**                                                                                     |
|:-----------------------------------------------|:----------------------|:----------------------------------------------------------------------------------------------------|
| `001proxima.avi`                               | 37.6 MB               | The camera looks at Proxima Centauri.                                                               |
| `001proxima-pm.avi`                            | 36.9 MB               | The camera looks at Proxima Centauri. Contains proper motions.                                      |
| `002north_ecl_pole.avi`                        | 35.0 MB               | The camera looks at the north ecliptic pole.                                                        |
| `002north_ecl_pole-pm.avi`                     | 37.2 MB               | The camera looks at the north ecliptic pole. Contains proper motions.                               |
| `003taurus_gemini_pleiades.avi`                | 42.6 MB               | The camera looks at Taurus, Gemini and the Pleiades.                                                |
| `003taurus_gemini_pleiades-pm.avi`             | 44.1 MB               | The camera looks at Taurus, Gemini and the Pleiades. Contains proper motions.                       |
| `003taurus_gemini_pleiades_ECLIPTIC.avi`       | 46.2 MB               | The camera looks at Taurus, Gemini and the Pleiades. Contains the ecliptic grid.                    |
| `003taurus_gemini_pleiades_ECLIPTIC-pm.avi`    | 49.0 MB               | The camera looks at Taurus, Gemini and the Pleiades. Contains proper motions and the ecliptic grid. |
| `004polaris_bigdipper.avi`                     | 34.4 MB               | The camera looks at Polaris and the Big Dipper.                                                     |
| `004polaris_bigdipper-pm.avi`                  | 31.9 MB               | The camera looks at Polaris and the Big Dipper. Contains proper motions.                            |
| `005south_ecl_pole.avi`                        | 39.8 MB               | The camera looks at the south ecliptic pole.                                                        |
| `005south_ecl_pole-pm.avi`                     | 35.7 MB               | The camera looks at the south ecliptic pole. Contains proper motions.                               |


## Catalog and other details

The videos have been produced using the [Partiview](http://virdir.ncsa.illinois.edu/partiview/) software and some specially developed scripts.
The catalog that has been used is the one used in the free version of the [Digital Universe](http://www.amnh.org/our-research/hayden-planetarium/digital-universe)
by the [AMNH](http://www.amnh.org/our-research/hayden-planetarium/). It basically contains the Hipparcos and Gliese catalogs
along with other catalogs for special objects (Dwarfs, Exoplanets, Pulsars, etc.). Find more information in the
Digital Universe webpage: <http://www.amnh.org/our-research/hayden-planetarium/digital-universe>.


## Credits

These videos have been produced by [Toni Sagristà](http://www.tonisagrista.com "Personal webpage") (<tsagrista@ari.uni-heidelberg.de>) with the
collaboration of Dr. Stefan Jordan (<jordan@ari.uni-heidelberg.de>)
using the [Partiview](http://virdir.ncsa.illinois.edu/partiview/) software and some Python scripts.

Below is the list of supporting institutions.
- The [DLR](http://www.dlr.de/).
- The [BWT](http://www.bmwi.de/), Bundesministerium für Wirtschaft und Technologie.
- The [ARI](http://www.ari.uni-heidelberg.de)/[ZAH](http://www.zah.uni-heidelberg.de/).


## License

These videos are published under the [LGPL license](https://www.gnu.org/licenses/lgpl.html).